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Registered
2006 WRX
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611 Posts
No, a 6-speed is stronger than the RA 5speed. The EJ257 is a newer engine therefore it should be more reliable than an engine over 10 years old.
 

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Registered
GF OBS-T, GM RS EJ20, SF EJ20
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4,973 Posts
Are you asking if a V4 STi RA swap is better than a 1. V4 STi swap or 2. a USDM STi swap?

If you are asking #1 I'd say yes.
If you are asking #2 I'd say no.

I have a V2 STi RA swap & I have to say the engine & tranny seemed heavier that what I am used to for Subaru parts - ? if it was because of the closed deck & RA gears...?...
 

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Registered
98 Impreza 3.4L Turbo
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3,294 Posts
Better is such a general term.

Bang for the buck? Yea, it's better.
Installation? Yea, it's better.
Reliability? No, it's not better
Emissions? No, it's not better
Theoretical performance? No, it's not better
 

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Free!
01 RSTI / 03LeggyH6
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6,936 Posts
Type RA Trans has ratios better suited for track use. I have an 04 STI motor (COBB St.2) + Ver.4 Type R Trans and 4.44 diff in my GM6 and have had no issues. If you want to run a ej257 and a bigger turbo then you should go with the 6 speed, though the 3.90 gearing will require some extra shifting on the track.
There's some helpful info on this page:

http://www.gearhack.com/myink/ViewPage.php?file=docs/Subaru Transmission Chart
 

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AYVI Motorsports
White 98 Impreza/06WRX
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440 Posts
big difference between a USDM ej257 Sti, and a V4 EJ20k STi RA ...

the V4 RA/ STi RA trannies are stronger then the V4 STi trannies since the gears are different, and the Ratios on the RA are shorter they have 4.44 FD and the ratios are VERY short. IMO the 6 speed would be more practical for a DD esecially if you like cruising at high speeds on the highway. The RA might have a advantage on the track

As far as the engine goes I think the RA has small internal differences, but extra power mostly comes down to a really aggressive tune that wouldn't be good with US 93 oct gas.
 

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Premium Member
RSTI
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6,844 Posts
The trans differences between the RA and the regular spec STI aren't that big. RA has lower gears. So maybe in that regard its stronger but the gears aren't any more reinforced or anything. STI and STI RA's both have 4.44 FD. If I were to do it over again I'd get the 6 speed because driving at freeway speeds with RA gears and 4.44FD is terrible. 70mph is about 4k rpm's.

Pretty sure the engines are the same. Cams can vary but thats about it. Get a USDM swap. It's much easier in the long run and way more reliable.

cheers

poorman


big difference between a USDM ej257 Sti, and a V4 EJ20k STi RA ...

the V4 RA/ STi RA trannies are stronger then the V4 STi trannies since the gears are different, and the Ratios on the RA are shorter they have 4.44 FD and the ratios are VERY short. IMO the 6 speed would be more practical for a DD esecially if you like cruising at high speeds on the highway. The RA might have a advantage on the track

As far as the engine goes I think the RA has small internal differences, but extra power mostly comes down to a really aggressive tune that wouldn't be good with US 93 oct gas.
 
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